This application claims the priority of German application 198 58 328.1, filed in Germany on Dec. 17, 1998, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a lightweight mobile bridge with a road deck, upper belts, side walls, and lower belts.
Fiber materials have high rigidity and strength in proportion to their specific density. Because of this property they are of interest for lightweight applications. These materials have considerable advantages when the fibers can be stressed in their lengthwise direction.
Two types of applications of composite fibers in bridge construction are known:
The structure with the exception of the force-introducing hardware is made from composite fibers;
Parts of a structure are replaced by composite fibers.
Extremely strict requirements in terms of weight, dimensions, rigidity, and strength are placed on movable bridges, so that the use of composite fiber materials is advantageous. However, there are two problems with the use of composite fibers. If the total structure is made of composite fiber material, the bridge becomes very expensive. When partial use is made of composite fiber material, many of the advantages of composite fiber construction disappear due to the differing thermal expansion behaviors of metal and composite fibers.
These problems are solved by preferred embodiments of the present invention which provide for a lightweight mobile bridge made of a plurality of bridge sections with a road deck, upper belts, side walls, and lower belts, wherein the road deck is composed of a plurality of transverse plates, wherein the side walls are undulating, and wherein the upper belts and/or the lower belts are made of composite fibers and fastening elements are present, which connect the side walls and belts to each other.
The subject of the invention is a bridge structure that can be implemented in a composite fiber-metal construction. Components in which the use of composite fibers has a relatively minor advantage over metal such as the shear ribs of the side walls are made of metal. Components in which the use of composite fibers is a major advantage, such as the belts of the bridge on which the stress is uniaxial, are made of composite fibers.
In this way, the costs are kept low by the effective use of high-strength composite fibers. The problem of thermal stress that then arises is solved by forming the metal parts of the bridge in such a way that they do not take up any forces in the lengthwise direction.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.